Hermetically sealed explosive cartridge



Feb. 2, 1954 C W. MUSSER ETAL HERMETICALLY SEALED EXPLOSIVE CARTRIDGE Filed May 22, 1951 INVENTORS. QWALTON MUSSER. NO QR MAN K. TURNBULL.

ATTORNEIS Patented Feb. 2, 1954 UNIT so STATE-S are-NT orsrcs HERM'ETICALLY SEALED EXPLOSIVE GARTRIDGE G Walton-Masse Philadelphia, Pa., amfNbrma'n' K. Turnbull; Pitman, N-Z J., assignors to tlie United Stfat'esmf' America as represented by the:- Secretary ofsthe' Army Application May. 22, 1951,.,SerialIlNo..227,587

(Granted underT-itle 35,.U. S. Code (1952:),-

sec. 266.)

The invention described herein may be manufacturedandused byor-for the Government for governmental purposes without the payment of any-royalty thereon:

Our invention relatesbroadly to ammunition and explosive devices, and; while not limited so'le- 1y thereto, has particular'reference to the explosive cartridges used insome personnel. catapults and canopy removers installed in high speed air:- craft. A cartridge embodying our concept can beseen in U. S. Patent 2,541,087, Safety Device for CatapultingPassengers from Aircraft, which was granted C W Musseron' February 13 1951.

The use of personnel catapults andcanopy'removers. in modern, high. velocity aircraft has made necessary the development of a' suitable small, light weight, compact and highly efficient explosive cartridge which. would be adequately protected from incursion by water,v moisture,

microscopic: flora and. fauna, ortother harmful agents. Until our. invention; an explosive car.- tridge fulfilling those stringent requirements .was not known.

As thoseskilledinithe' art well'. know; priorJart explosive cartridges designed for catapult use essentially have typically comprised. a: casing which has a percussionprimer mountedtinthe closed end so that the" bottom of." the primer.s cup is substantially coplanar'withthefclosed end of the casing. Extendinginside the casing from its closedend, and axially juxtapositione'diinLre+ l'ation to the primer; there generallyi'hasbeen employed acylindrical. perforated tubes which contains a booster powder. charge. 'Ihetcasingzis filled nearly to thetop of its open. end with a main explosive charge which; is prevented: from leaking out by means of aretaining'disc: fitted into theca'singsopenend. In ordentoisealsuch cartridges against infiltration by deleterious agents'usewas made of a sealing compoundib'etween the percussion'primer and thecasing; and between theretaining: discand the casing:

In the light of our present inventiontheseprior art explosive cartridges possess many undesirable features which-have rendered them unqualifiecl for application to aircraftpersonnel'catapults andcanopy removers. For. one; the useroif the axially extending perforated tube containing the booster powder charge necessitated a largerand heavier explosive cartridge in' order' to obtain the same effect. as our cartridge; Another disadvantage wasthe settingback (i. e; thetendsency to'be. blown out of itsrecess) upon, firing of l the percussion. prim or with. theattendant loss of the cartridges efficiency. A further disad- 2.. vantage wasdue to the fact that the'sealing compound invariably deterioratedduring storage of the cartridges, or as a result of attack by adverse agent, so asto become inadequate in a comparatively short time.- This condition made the components inside :the cartridge vulnerable -to attack by infiltration of harmful matter, thus jeopardizing theproper operation ofthecartridge in time of need, as well as the life: of aircraft passengerswho' rely on the cartridge to actuate life-saving catapult devices.

In our novel.- cartridger we? have eliminated? the inherent disadvantages: of prior art devices by reducing; to: a minimum the number of possible sites: of entry into the 'cartridges: interior: byunT- desirable matter. In. addition,. we. have sealed the'ca-rtridge in a: novelrnann'er with the aid 01 a resilient-ring.

Our cartridge comprises a onepiece, can-like casin in the:open end of: which-is seated a head. The head contains, essentially,. a. retainingiplat'e, hammer, a percussion primer, radial fire holes, and abooster charge. Between the-head: and the c1osed-.end: of the casing we-have positioned the: mainpowder charge which, for illustrative purposes, takes a cylindrical stick form. The open'end of the-casing. is closed by means of a thin cover plate, which passes close to the-outer end oithe hammer, and is sealedin novel'fashion by forming: the" rim of" the casing against aresilient ring. Thering, which preferably is made of rubber or. a rubber-like material, is thereby forced against. the cover plate and. against: the casing to form. acontinuous: seallaround the casings open end.. All:.exterior:parts of our"car. tridge are-f made-of: such durable: material, oriare surface treated in: such. away as to: render: them unaffected: by conditions? likely ever to be: encountered anywherefin'the-world.

One object of our" invention is to' provide a small, compact;,light Weight, and? highly efficient explosivecartridges.

Another-object is to: provide an explosive cartridge in which axial-displacement of. thezprimer during: clischa-rge'rof the cartridge is preventedby a member include'd'within' th'e cartridge.v

Yet another object: is. toprovide an explosive cartridge in which the booster powder charge is situate: in an annular ring surrounding and in proximity to a percussiorrprim'er;

A' further: obj ecti is-toi provideani explosive car.- tridgeutilizinga avon'eepiece; can-like casingzwhose closed end is readily blown: openrupon': firing, the cartridge.

A still further object is to provide an explosive cartridge in which the percussion primer is fired through an intermediary plate closing the canlike casing.

A final object is to provide a hermeticallysealed explosive cartridge in which the sealmg means in unaffected by water, moisture, microscopic organisms, or other harmful agents through a wide range of temperature and pressure variations.

The foregoing and other objects and advantages of our invention will become apparent from an inspection of the following specification and the accompanying drawing.

During the following description of our invention, the word inner will refer to parts located toward the cartridges closed end, and the word outer will refer to parts toward the cartridges open end.

From the drawing our cartridge will be seen to consist of a cylindrical, drawn metallic casing having a closed end 5 and an open end 6 having a larger diameter. The open end is provided with a circumferential shoulder I which is formed by the junction of the larger and smaller diametrical portions of the casing. Resting upon shoulder l and extending part way into the smaller diameter portion of the casing is a head 8. Axially located in the outer end of head 8 is a recess 9 which accommodates a hammer in and an explosive primer ll. The inner surface of head 8 is provided with a continuous annular groove l2 which contains a booster charge l3 which is confined within the groove by means of an inflammable disc 24 made of such material as cellulose nitrate or the like. This disc, in turn, is held in place by means of a retaining spring l5. Extending radially outward from the inner end of the primer to the annular groove are multiple fire holes Is. A main powder charge 22 in cylindrical stick form is confined within the cartridge between head 8 and the casings closed end 5. Note that the fire holes are sloped between the primer and the booster charge so as to efiect front face ignition (i. e. the face nearer the main powder charge) of the booster charge.

Hammer l6 comprises a larger diameter portion It, having a tip 23, and a smaller diameter portion l1, and is held in position in the following manner. The outer surface of head 8 is provided with a recess which accommodates the retaining plate Hi. This plate is positioned within head 8 so that both the outer surface of the head and of the retaining plate are substantially coplanar. Retaining plate !8 contains a centrally located recess is which is somewhat smaller in diameter than larger portion l6 of the firing pin, so that, when that plate is in place within the head, the tip of the hammer is held in light contact with primer H. Thus, the hammer and the primer are confined in head 8.

The open end of the casing is covered by a thin metallic cover plate 2%] which is accommodated therein and is sealed by means of a resilient ring 2i, which rests upon the cover plate. The resilient ring is held in a stressed condition against the cover plate by means of the open end of the cartridge case which is rolled or otherwise formed so as to press against the resilient ring.

The detonation of our inventive cartridge takes place in the following manner. A firing pin (not shown), which forms part of the personnel catapult or canopy remover in which our cartridge is used, strikes cover plate or disc 20. This disc is fiexible enough to allow the impact of the firing pin to depress hammer EU. The moving hammer strikes percussion primer II and thereupon detonates it. Fire from the primer travels along multiple fire holes l4 and ignites the booster charge I3. Fire from the booster charge simultaneously consumes cellulose nitrate disc 24 and reaches main powder charge 22. Since the side wall and outer end of the cartridge generally are supported by members forming part of the personnel catapult or canopy remover, force from the exploding main charge is liberated from the inner closed end 5 of the cartridge case which is blown open.

From the foregoing it will be apparent that we have provided a small, compact, light weight and highly eflicient explosive cartridge; that we have provided an explosive cartridge in which axial displacement of the primer during discharge of the cartridge is prevented by a member included within the cartridge; that we have provided an explosive cartridge in which the booster powder charge is situate in an annular ring surrounding and in proximity to the percussion primer; that we have provided an explosive cartridge utilizing a one piece, can-like casing whose closed end is readily blown open upon firing the cartridge; that we have provided an explosive cartridge in which the percussion primer is fired through an intermediary plate closing the canlike casing; and, that we have provided a hermetically-sealed explosive cartridge in which the sealing means is unaffected by water, moisture, microscopic organisms, or other harmful agents through a wide range of temperature and pressure variations.

The invention here described for illustrative purposes is but one form of our concept which is capable of great variation and modification without departing from its original spirit and scope. For that reason, we do not wish to be limited by the narrow confines of the embodiment here discussed, but rather only by the metes and bounds of the appended claims.

We claim:

1. An explosive cartridge comprising: a, hollow casing having an opening thereinto and provided with an internal shoulder facing said casings opening; a head fitting inside said casings opening and resting upon said shoulder, said head having a central opening thereinto continuous with a fire hole that communicates with the opening into said casing; a percussion primer located in said heads central opening; an explosive charge in said casing; a hammer movably mounted in said heads central opening axially adjacent to and in contact with said primer; a retaining plate adjacent the outer end of said head and having a central opening in alignment with but of lesser diametrical dimension than said hammer, whereby to prevent any appreciable endshake of said hammer; a cover plate resting upon said retaining plate close to the outer end of said hammer; and a rubber sealing ring secured in contact with said cover plate so as simultaneously to exert a pressure thereagainst and against the side Wall of said casing at its junction with the cover plate, whereby hermetically to seal the casing against undesirable admittance therein of all exterior, atmospheric agents through a wide range of temperature and pressure variations.

2. The combination in an explosive cartridge of: a hollow casing having a single opening thereinto and provided with an internal shoulder facing said casings opening; a head fitting inside said casings opening and resting upon said shoulder, said head having a central opening thereinto continuous with a fire hole that communicates with the opening into said casing; a percussion primer positioned in said heads central opening; a booster charge in said head adjacent the fire hole therein; an inflammable member to confine said booster charge in said head; a retaining spring to confine said inflammable member in said head; an explosive charge positioned in said casing so as to be detonated readily upon ignition of said inflammable member by said booster charge; a cover plate resting upon the outer end of said head proximal to the outer end of said primer; and a resilient ring secured in contact with said cover plate so as to exert a force thereagainst, whereby to prevent access to the cartridges interior of all harmful atmospheric agents through a wide range of temperature and pressure variations.

3. In an explosive cartridge, the combination of: a hollow casing having a single opening thereinto and provided with an internal shoulder facing said casings opening; a head fitting inside said casings opening and resting upon said shoulder, said head having a central opening thereinto continuous with a fire hole that communicates with the opening into said casing; a percussion primer positioned in said heads central opening; a booster charge in said head adjacent the fire hole therein; an inflammable disc to confine said booster charge in said head; a retaining spring to confine said inflammable disc in said head; an explosive charge positioned in said casing so as readily to be detonated upon ignition of said inflammable disc by said booster charge; a hammer movably mounted in said heads central opening axially adjacent to said primer and in contact with said primer; a cover plate in said opening resting upon the outer end of said head proximal to the outer end of said primer; and a resilient ring secured in contact within said cover plate so as to exert a stress thereagainst, whereby to seal said opening against leakag thereinto of unwanted atmospheric agents through a wide range of temperature and pressure variations.

4. An explosive cartridge comprising: a hollow casing having a single opening thereinto and provided with an internal shoulder facing said casings opening; a head fitting inside said casings opening and resting upon said shoulder, said head having a central opening thereinto continuous with a fire hole that communicates with the opening to said casing; a percussion primer in said heads central opening; a booster charge in said head adjacent the firing hole therein; an inflammable disc to confine said booster charge in said head; a retaining spring to confine said inflammable disc in said head; an explosive charge located in said casing so as readily to be detonated upon ignition of said inflammable disc by said booster charge; a hammer movably mounted in said heads central opening axially adjacent to said primer and in contact with said primer; a retaining plate in said casings opening adjacent the outer end of said head and having a central opening in alignment with but of lesser diametral dimension than said hammer, whereby to prevent any appreciable endshake of said hammer; a cover plate resting upon said retaining plate close to the outer end of said 6 hammer; and a resilient ring secured in contact with said cover plate so as to exert a, pressure thereagainst, whereby to hermetically seal said casings opening through a wide range of temprimer in said heads central opening; a booster charge in said head adjacent the firing hole therein; an explosive charge located in said casing so as readily to be detonated upon ignition of said booster charge; a hammer movably mounted in said heads central opening axially adjacent to said primer and in contact with said primer; a retaining plate in said casings opening adjacent the outer end of said head and having a central opening in alignment with but of lesser diametral dimension than said hammer, whereby to prevent any appreciable endshake of said hammer; a cover plate resting upon said retaining plate close to the outer end of said hammer; and a resilient ring secured in contact with said cover plate so as to exert a pressure thereagainst, whereby hermetically to seal said casings opening through a wide range of temperature and pressure variation.

6. An explosive cartridge comprising: a hollow casing having a central opening thereinto and provided with an internal shoulder facing said casings opening; a head fitting inside said casings opening and resting upon said shoulder, said head having a central opening thereinto continuous with a fire hole that communicates with the opening to said casing; a percussion primer in said heads central opening; an explosive charge located in said casing so as readily to be ignited upon detonation of said primer; a hammer movably mounted in said heads central opening axially adjacent to said primer; retaining means in said casings opening adjacent the outer end of said head for preventing any appreciable endshake of said hammer; and means for hermetically sealing said casings opening including a cover plate which is capable of receiving and transmitting a detonating blow to said hammer for action, in turn, upon said primer.

C WALTON MUSSER. NORMAN K. TURNBULL.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 133,496 Storer Nov. 26, 1872 753,035 Bennett et al. Feb. 23, 1904 963,911 Loeble July 12, 1910 1,192,538 Leslie July 25, 1916 1,491,000 Brandt et a1 Apr. 22, 1924 2,362,738 Yarbrough Nov. 14, 1944 FOREIGN PATENTS Number Country Date 288,482 Germany July 24, 1919 518,995 France Jan. 14, 1921 574,876 Great Britain Jan. 24, 1946 

